The invention relates to the field of batteries, and particularly to an electrolyte and a lithium ion battery comprising the same. The electrolyte comprises an organic solvent, a lithium salt and additives, wherein additives comprise an alkenyl carboxylic acid halogenated silane ester compound and a sulfur-containing lactone compound; when the electrolyte contains the two kinds of additives at the same time, the decomposition of the electrolyte on the surface of the electrode can be effectively restrained; a low-resistance stable film can be formed on the surface of the electrode by the alkenyl carboxylic acid halogenated silane ester compound; meanwhile, the sulfur-containing lactone compound participates in the film formation, so that the sulfur-containing high-thermal-resistance film is formed on the surface of the electrode; and therefore, the high-temperature performance of the battery is greatly improved.